Privacy-Preserving Cross-Zone Ride-Matching for Online Ride-Hailing Service

Algorithm 1

Adjacent zone search.

(1)	Input: the upper right corner coordinates and lower left corner of zone z
(2)	The distance between the nearest driver and the rider in zone z
(3)	The coordinate of the rider
(4)	Output: zones array that nearest driver may exist
(5)	is initialized to empty
(6)	if , then add into
(7)	if , then add into
(8)	if , then add into
(9)	if , then add into
(10)	if , then add into
(7)	if , then add into
(11)	if , then add into
(12)	if , then add into
(13)	return